The present disclosure relates to high temperature fluidized bed systems, particularly fluidized bed reactors such those used in the production and recovery of metals, metal oxides, and chemical conversion products of materials, as well as in energy generation conversion units.
Various ores (e.g., titanium-bearing ores, ferrous ores, etc.), coal, slags and metals are processed in high temperature fluidized beds. Fluidized bed systems are also used for coking, as well as for chlorination of feedstock. Power plants also employ high temperature fluidized beds, such as those used in biomass high temperature energy conversion, waste-to-energy systems, organic fuel processing, and recycled fuel operations. There are several types of reactor beds: fixed bed, slurry bed, fluidized bed boilers, circulating fluidized beds and bubbling fluidized beds. Typically, circulating fluidized bed boilers are more efficient than bubbling fluidized beds since particulate and reactants are mixed at a higher velocity and react more efficiently with better conversion rates than low particle velocity bubbling fluidized beds.
Typically, fluidized bed systems have a dense hot face, or working lining, made of refractory fire brick, perhaps several rows, as well as back up layers of insulating fire brick between the steel shell and the refractory brick lining. The size of these bricks are traditionally such that a single person can easily handle a brick, a classic example being 4.5 inches in width by 9 inches in length and 3 inches in thickness. The refractory bricks are mortared together. However, even with the advent of super dense, low porosity, hot face brick created to last longer in service, the mortar is still the weakest link in the refractory process. The mortar is the prominent source of failure. When the mortar fails, the bricks begin to corrode at those contact areas lacking mortar and, with time, shift and fall out of place. In addition, the production unit of the fluidized bed tends to vibrate during service, and that movement is an additional contributor to mechanical failure at the mortar-brick contact surface.
In fluidized bed reactors which operate hot enough to require the use of ceramic refractories where acids are present, the refractory bricks can also act as a physical and thermal protection barrier to acid reactions with the outer steel shell of the fluidized bed reactor containment unit. A joint failure in these reactors provides an access route for corrosive gases to migrate more easily to the steel shell and condense upon it, potentially degrading the steel shell.
Other problems with current refractory brick designs used in fluidized bed reactors include:                lack of a strong mortar bonding on high fired brick, particularly in the case of extremely high fired brick which has extremely low porosity which makes it nearly impossible for mortar to bond well with the brick face;        a high number of mortar joints exist in the lining with potential for early failure at all of them;        mortar joints at each bonding face of tile or mortar are areas of low strength, high porosity and lower chemical resistance than the brick;        vibration movement commonly experienced by entire containment vessel during processing allows for debonded tile or brick to shift and eventually fall out, collapsing regions of side walls in the combustor zone;        abrasion from the fluidizing media and particulate matter will wear the mortar joints;        tiles or brick require joints, mortar and labor for installation, an exceptionally labor intensive process;        the mortar must be allowed to dry after the brick have been placed to a critical stack height to prevent wall collapse which adds time; and/or        dry out is required to eliminate moisture from the mortar, along with the possibility of moisture release or inclusion of moisture in the chemical process which can reduce the reaction speed and/or contaminate the process.        
While a variety of devices and techniques may exist for fluidized bed reactor systems, it is believed that no one prior to the inventors have made or used an invention as described herein.
The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown.